FISU – Fill In Signalling Unit
# A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
< Back to glossary

FISU – Fill In Signalling Unit

The Fill In Signalling Unit acts as flag in TDM (Time Division Multiplexing) based SS7 (Signalling System No.7) signalling networks when there is no other information to send. The FISU consists of MTP3 (Message Transfer Part – Level 3) routing information and is sent in place of flags in idle periods. It also serves to verify the integrity of the link as the receiving side will performing a FCS (Frame Check Sequence) on the FISU.

Enhance your knowledge further with our OnlineAnytime Training.

We have package options designed for individuals, teams and organisations. Our packages include:

5G content and courses continually being added
Access to NetX...supporting in understanding network complexities
ITP Certified courses also providing CPD learning credits
Access via Tablet, Desktop and Smartphone...maximising learning opportunities
View our package options

Need more information? Want to know more about what we do?
Contact Us or Call +44 (0) 1524 844669

Working together with